Clutch mechanism



April 28, 1942. J. F. CULLIN CLUTCH MECHANISM Filed April 21, 1941ZZZ/61157 JUTsparZ Uzi/[Zia Patented Apr. 28, 1942 CLUTCH MECHANISMJasper F. Cullin, Detroit, Mich., assignor to twothirds to Lou Mervis,Lock Haven, Pa.

Application April 21, 1941, Serial No. 389,583

17 Claims.

The invention relates to clutch mechanism of the type adapted for use instarters for internal combustion engines.

In starting internal combustion engines, a backfire sometimes occurs andthis results in a high torque, opposed to the force applied for drivingthe engine in the operating direction or the engine may be stuck so thatthe torque required to start it may be excessive. If the driving memberof the starter is engaged by the driving means therefor, a backfiresometimes produces torque which may be destructive of the mechanism ofthe starter. For example, in starting mechanism which includeseccentricoperated pawls and a ratchet wheel, such as exemplified in myapplication for patent for Starting mechanism for internal combustionengines, Serial No, 343,762, filed July 3, 1940, issued as Patent No.2,256,466 on Sept. 23, 1941, the wheel remains engaged by the pawlsduring a starting 1 operation. If a backfire occurs While the pawls areengaged with the ratchet wheel, the torque from the engine istransmitted to the ratchet wheel and pawls. This torque may result inbreakage or render the starter inoperative. It is also desirable toprovide in the starter a resilient drive for the crankshaft.

One'object of the invention is to provide a clutch mechanism with amaximum torque throw-out so that the driving member thereof will beuncoupled or disengaged from the driven element in the event of abackfire or when the torque required to turn the engine is excessive forany other reason.

Another object of the invention is to provide an improved clutchmechanism which is adapted for engine starters, which includes a maximumtorque throw-out and a resilient driving connection between the drivingmember or the starting mechanism and the driven member.

Another object of the invention is to provide a clutch mechanism of thistype which is simple in construction and eflicient in operation.

Other objects of the invention will appear from the detaileddescription.

The invention consists in the several novel features which arehereinafter set forth and are more particularly defined by claims at theconclusion hereof.

In the drawing: Fig. 1 is a view, partly in section and partly inelevation, illustrating a clutch mechanism embodying the invention inits inoperative or normally disengaged position. Fig. 2 is a similarview illustrating the clutch mechanism when the driving member has beenautomatically released by excess torque. Fig. 3 is a section on line 3-3of Fig. 1. Fig. 4 is a section taken on line 4 4 of Fig. 2.

The invention is exemplified with the shaft a of an internal combustionengine and a case b which encloses the clutch mechanism and is usuallysecured to one end of the engine. The clutch mechanism comprises anouter annular driving member or wheel 6, which is provided with ratchetteeth 5 and is adapted to be driven to start the engine by a pair ofpawls 1 and 8, which are journaled on oppositely disposed eccentrices 9and I!) on a shaft II. The pawls are each provided with a counterweightI2 for normally holding their operative ends l3 disengaged from theratchet wheel or member 6, and are controlled to engage and disengagethe ratchet for the operation of the starting mechanism by a pair ofresilient arms 14 engaging the pawls I, 8, respectively, and secured toa shaft I5 which is usually manually shiftable by means of a handle.Shaft H and eccentrices 9 and 10 may be driven by an electric motor, asexemplified in my application Serial No. 343,762, or by any suitablemeans, to operate pawls l and 8.

The clutch mechanism also comprises a spider or inner member whichincludes an annulus l6 which is keyed to the engine shaft a and integraloutwardly extending arms or lugs l1; an intermediate member whichincludes a ring or annulus l8 and integral inwardly extending lugs orabutments I9 adapted to be engaged by the arms ll of the spider; andcoil springs 20 which are loaded, as hereinafter described, and extendbetween abutments I9 on the intermediate member and the arms I! of thespider, respectively. Ratchet wheel 6 is in the form of a ring which issupported on, fits around, and is rotatable relatively to, ring 18 ofthe intermediate member. The outer ends of arms I! extend to and fit theinner periphery of ring N3 of the intermediate member and support thelatter coaxially with the shaft a. Annular plates 2| are secured to ringl8 by through-rivets 22 and lap the sides of member 6 to retain saidmember against endwise movement relatively to ring I 8 and arms I! ofthe spiderfit between plates 21 and secure the latter and ring I8against endwise movement relatively to shaft a.

A pin or locking member 24 is radially and pin 24 is provided at itsinner end with a tapered portion 23 which fits in, and is adapted topass into a corresponding tapered conical socket 29 in the outerperiphery of annulus N5 of the spider which is keyed to shaft a. Thelocking pin 24 is adapted, while its outer tapered end 26 is engagedwith socket 2'! in the driving member 6, to be locked in such engagementby a peripheral portion [6 of the annulus 16 of the spider. Pin 24 isalso adapted to be locked in socket 29 in the annulus 16 of the spiderby the inner periphery 6 of the outer driving member 6. When pin 24 isengaged with socket 21 in driving member 6, the latter will be drivablyconnected by the pin to the intermediate member and the latter will beadapted to drive the inn'er member or spider through the springs 2!).When pin 2 is engaged with socket 29 in the inner member or spider, itwill be disengaged from driving member 6 and permit relative rotation ofthe driving member 6 and the intermediate memher which is then lockedtomember It by the pin. The tapered ends of the pin 24 and the taper ofsockets 21- and 29 arev adapted to alternately cam the-pin from onesocket into the other, responsively to torque.

The operation will be as follows: when the starter is not inuse, pawls 1and 8' will be held disengaged from the ratchet teeth on the drivingmember 6; pin 24. will be in the position illustrated in Fig. 1; and itsouter end will be locked in socket 21 of the member 6 by the outerperiphery ifi of annulus lb of the spider, as shown in full lines inFig.1.

To start. the engine, the operator will rock arms. in to press pawlsv 7and 8 into engagement with. ratchet teeth 5 of wheel 6 and theeccentrices 9' and I will be continuously driven to alternately and,successively engage teeth and drive the ratchet wheel 6. The springs 29are loaded for compression apredetermined normal maximum torque, whichwill start the engine before pin is registers with socket 29 in thespider. When the torque required to turn the engine does not exceed saidmaximum, pin 2 willbe held locked to ratchet wheel 6 by peripheralportion of the spider. When the engine starts, wheel 6 will overrunpawls 1 and 8, and'the torque on ratchet wheel 6 from the pawls will bereleased and springs 2i) will rotate the intermediate member and pin 24until arms H on the spider engage abutments [9 on the intermediatemember. It is not necessary for the operator to immediately disengagepawls l and 8 after the enginehas started. If the torque required toturn the engine exceeds the predetermined maximum, or in the event of abackfire which produces an excessive opposed torque from the enginethrough the spider, springs 1 will be compressedsuiificiently to permitpin 24 i to register with the socket 29 in the inner memsocket 21 in theratchet wheel 6. When pin 24" has been cammed out of socket 27, theinner periphery B of wheel 6 will hold pin zfi'engaged with the spiderand uncoupledirom the ratchet wheel, as illustrated in Fig. 2. The drivewheel 6- will then be free to be driven by pawls l and 8- forapproximately one revolution and wheel E rotated toag-a in bring pinZ'Ginto registry' for use in starters for internal combustion engines inwhich the outer driving member resiliently drives the engine in startingand is automatically uncoupled from the intermediate member responsiveto torque in excess of a predetermined maximum.

The invention is not to be understood as re stricted to the details setforth, since these may be modified within the scope of the appendedclaims, without departing from the spirit and scope of the invention.

Having thus described the invention, what I claim as new and desire tosecure by Letters;

Patent is:

1. Clutch mechanism comprising a. wheel, an

inner member, an intermediate member, said.

wheel and members being connected for relative rotation, resilientdriving means between said members, a locking element movably mount-- edon the intermediate member for driving the intermediate member, from thewheel and re sponsive to torque from the wheel for uncoupling the wheeland intermediate member, and means on the wheel for holding the elementuncoupled from the wheel.

2. Clutch mechanism comprising a wheel, an

inner member, an intermediate member, saidwheeland members beingconnected for rela-- tive rotation, resilient driving means between saidmembers, a locking element movably mounted on thesintermediate memberfor driving the intermediate member from the wheel and responsive totorque from the wheel in one directionfor uncoupling the wheel andintermediate member, means on the wheel for holding theelement uncoupledfrom the wheel, and means on the inner member operable by said resilientdriving means for shifting the element to couple the wheel andintermediate member;

3. Clutch inechanism comprising a wheel, an' member, said inner member,an intermediatewheel and members being conneeted' for relative rotation,resilient driving means between said members, a locking element movablymounted" on the intermediate member for driving the intermediate memberfrom the wheel and responsive to torque from the-wheel in one directionfor.

uncoupling the wheel andintermediate member, means on the 'wheel'forholding the elementuncoupled from the wheel, means on the inner memberresponsive tosaid resilient drivingmeans for shifting said element. tocouple the wheel and the intermediate members, and means on the innermember for holding. the element coupled to the Wheel.

4. Clutch mechanism comprising a wheel, an

inner member; an intermediate member, said.

wheel and members being connected for relative rotation, resilientdriving means between said,

members, a locking element movably mounted on the intermediate memberfor'driving the intermediate member from the wheeland responsive totorque from the wheel in one direction for uncoupling; the wheel andintermediate member, a peripheral suriaceon the wheel for holding theelement uncoupled from the wheel, means on members, a locking pinslidably mounted on the 1 intermediate member for driving theintermediate member from the wheel, means between the wheel and the pinresponsive to torque from the wheel for slidably shifting the pin touncouple the wheel and intermediate member, and means on the wheel forholding the pin uncoupled from thewheel.

6. Clutch mechanism comprising a wheel, an inner member, an intermediatemember, said wheel and members being connected for relative rotation,resilient driving means between said members, a locking pin slidablymounted on the intermediate member for driving the intermedi-, atemember from the wheel, means between the wheel and the pin responsive totorque from the wheel for slidably shifting the pin to uncouple thewheel and intermediate member, means on the wheel for holding the pinuncoupled from the Wheel, and means on the inner member for shifting thepin to couple the wheel and intermediate member.

'7. Clutch mechanism comprising a wheel, an inner member, anintermediate member, said wheel and members being connected for relativerotation, resilient driving means between said members, a locking pinslidably mounted on the intermediate member for driving the intermediatemember from the wheel, means between the wheel and the pin responsive totorque from the wheel for slidably shifting the pin to uncouple thewheel and intermediate member, means on the wheel for holding the pinuncoupled from the wheel, means on the inner member for shifting the pinto couple the wheel and intermediate member, and means on the innermember for holding the pin coupled to the wheel.

8. Clutch mechanism comprising a wheel, an inner member, an intermediatemember, said wheel and members being connected for relative rotation,resilient driving means between said members, a locking pin slidablymounted on the intermediate member for driving the intermediate memberfrom the wheel, means between the wheel and the pin responsive to torquefrom the wheel for slidably shifting the pin to uncouple the wheel andintermediate member, a peripheral surface on the wheel for holding thepin uncoupled from the wheel, means on the inner member for shifting thepin for drivably coupling the wheel and intermediate member, and aperipheral surface on the inner member for holding the pin coupled tothe wheel.

9. Clutch mechanism comprising a wheel, an inner member provided withoutwardly extending arms, an intermediate member on which the wheel isrotatably mounted and provided with inwardly extending abutments adaptedto be engaged by the arms, resilient driving means between the abutmentson the intermediate member and the arms on the inner member, a lockingpin slidably mounted in the intermediate member for driving theintermediate member from the wheel, the wheel being provided with asocket to receive the pin, torque responsive cam means for uncouplingthe wheel from the wheel.

10. Clutch mechanism comprising a wheel, an

inner member provided with outwardly extending; arms, an intermediatemember on which the wheel is rotatably mounted and provided withinwardly extending abutments adapted to be engaged by the arms,resilient driving means between the abutments on the intermediate memberand the arms on the inner member, a locking pin slidably mounted in oneof the abutments of the intermediate member for coupling and uncouplingthe wheel and the intermediate member, the pin being provided withtapered ends, the wheel and inner member being provided with socketsadapted to receive the ends of the pins respectively, said ends andsockets being torqueresponsive for uncoupling the wheel from the innermember, means ,on the inner member for holding the pin coupled to thewheel, and means on the wheel for holding the pin uncoupled therefrom.

11. Clutch mechanism comprising a wheel, an inner member provided withoutwardly extending arms, an intermediate member on which the wheel isrotatably mounted and provided with inwardly extending abutinentsadapted to be engaged by the arms, resilient driving means between theabutments on the intermediate member and the arms on the inner member,a, locking pin slidably mounted in one of the abutments of theintermediate member for coupling and uncoupling the wheel and theintermediate member, the pin being provided with tapered ends, the wheeland inner member being provided with sockets adapted to receive the endsof the pins respectively, said ends and socket being torqueresponsivefor uncoupling the wheel from the inner member, a peripheral surface onthe inner member for holding the pin coupled to the wheel, and aperipheral surface on the wheel for holding the pin uncoupled therefrom.

12. In clutch mechanism for an engine starter, the combination of atoothed wheel, means engagea-ble with the teeth for driving the wheel,an engine-rotatable inner member, an intermediate member within thewheel around, and rotatable relatively to, the inner member and to thewheel, a resilient driving connection between the members, a lockingelement movably mounted in the intermediate member for driving theintermediate member from the wheel and responsive to torque from thewheel while it is being driven and to torque produced by a backfire ofthe engine, for uncoupling the locking element and the wheel, means onthe wheel for holding the pin uncoupled from the wheel, and means on theinner member for holding the element coupled to the wheel.

13. In clutch mechanism for an engine starter, the combination of atoothed wheel, means engageable with the teeth for driving the wheel, anengine-rotatable inner member, an intermediate member within the wheelaround, and rotatable relatively to, the inner member and to the wheel,a resilient driving connection between the members, a locking pinslidably mounted in the intermediate member for driving the intermediatemember from the wheel and responsive to torque from the wheel and totorque produced by .a backfire of the engine for uncoupling the pin andthe wheel, means on the wheel for holding the pin uncoupled from theWheel, and means intermediate member, and means on the inner. member forholding the pin coupled to the on the inner member for'shifting the pinto'couple the wheel and intermediate member.

14. In clutch mechanism for an engine tarter, the combination of atoothed wheel, means engageable with the teeth for driving the wheel, anengine-rotatable inner member, an intermediate member within the wheelaround, and rotatable relatively to, the inner member and to the wheel,a resilient driving connection between the members, a locking elementmovably mounted in the intermediate member for driving the intermediatemember from the wheel and responsive to torque from the wheel and totorque produced by a backfire of the engine for uncoupling the lockingelement and the wheel, peripherally extending means on the wheel forholding the pin uncoupled from the wheel, means on the inner member forshifting the element to couple the Wheel and intermediate member, andperipheral means on the inner member for holding the element coupled tothe wheel.

15. In clutch mechanism for an engine starter, the combination of atoothed wheel, means engageable with the teeth for. driving the wheel,an engine-rotatable inner member, an intermediate member within thewheel around, and rotatable relatively to, the inner member and tothewheel, a resilient driving connection between the members, a lockingpin slidably mounted in the intermediate member for driving theintermediate member from the wheel and responsive to torque from thewheel and to torque produced by a backfire of the engine for uncouplingthe locking pin and the Wheel, peripherally extending means on the wheelfor holding the pin uncoupled from the wheel, means on the innermemherfor coupling the pin to the wheel, and peripheral means on the innermember for holding the pin coupled to the wheel.

16. In clutch mechanism, the combination of a wheel, an inner member, anintermediate member, resilient driving means between the inner andintermediate members, said wheel and members being mounted for relativerotation, a locking pin slidably mounted in the intermediate member andslidable to alternately lock together the intermediate member and theouter member and the inner and intermediate members andtorque-responsive for shifting the locking pin to lock the pin to thewheel or the inner member.

17. In clutch mechanism, the combination of an outer annular wheelprovided with a socket on its inner periphery, an inner member providedwith an annulus and arms and a socket in the outer periphery of theannulus, an intermediate member between the inner and outer membersprovided with abutments engageable with said arms, a resilient drivingconnection between the inner member and the intermediate member, alocking element slidablymounted in the intermediate member, the innerand outer ends of the pin and said sockets being tapered to shift theelement responsive to predetermined torque, the annulus of the innermember having a peripheral surface for holding said element engaged withthe Wheel, the Wheel having a peripheral surface for retaining thelocking element engaged with the socket in the annulus of the innermember.

JASPER F. CULLIN.

